Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N3/40—Investigating hardness or rebound hardness
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/0014—Type of force applied
  • G01N2203/0023—Bending
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
  • G01N2203/02—Details not specific for a particular testing method
  • G01N2203/026—Specifications of the specimen
  • G01N2203/0262—Shape of the specimen
  • G01N2203/0278—Thin specimens
  • G01N2203/0282—Two dimensional, e.g. tapes, webs, sheets, strips, disks or membranes

Definitions

• the invention relates to devices for determining the stiffness of flexible materials, wherein a guided attachment means for a sample of the flexible material with a position measuring device and a drive is coupled so that the fastening device is movable relative to a bending edge of the device for the sample.
• a known measuring technique is the bending stiffness tester according to the cantilever method according to DIN 53362.
• This tester has the disadvantages of an uneven feed rate of the bending test specimen due to manual operation, a visual determination of reaching the overhang length and a visual reading of the overhang length on a half millimeter scale.
• the visually determined overhang length is included in cubic power in the calculation of the bending stiffness.
• the bending test at the front edge does not remain linear and an assessment of the sample edge is not possible. Research has confirmed that these problems greatly affect the reproducibility of the results.
• the specified in claim 1 invention has for its object to automatically and simply determine the bending behavior of flexible materials.
• the means for determining the stiffness of flexible materials wherein a guided fastener for a sample of flexible material is coupled to a position measuring device and a drive so that the fastening device is movable relative to a bending edge of the device for the sample, are characterized in particular by their simple Realization with automatic determination of the bending behavior.
• an optical measuring arrangement for non-contact measurement of the overhang of the self-weight bending sample is arranged in the direction of movement of the sample after the bending edge of the device, wherein the measuring arrangement consists of a plurality of photodetectors on the bending edge and at least one light emitter.
• the position measuring device, the drive and the optical measuring arrangement are connected to a control device such that the measurement of the position of at least a portion of the overhang over the sample leading edge of the self-bending sample in the direction of movement of the sample according to the positions of the Positionssmesseimichtung and the photodetectors he follows.
• the facilities are characterized by a high reproducibility of the measurement results.
• the sample widths may be 25 mm, 50 mm and 200 mm, for example.
• the feed rate is variably selectable, whereby a constant feed rate is ensured during the test.
• the applied optical measuring arrangement for non-contact measurement of at least one area of the sample leading edge also advantageously allows a graphical representation of this area, thus the shape of this area of the sample leading edge and, as a consequence, the bending behavior over at least this area.
• the device can advantageously be operated comfortably and easily.
• the device is suitable for both industrial and scientific application.
• the optical measuring arrangement consists of a plurality of spaced light barriers, wherein the light emitter spaced from the bending edge and the photodetectors are arranged at the bending edge, so that the position and consequently the shape of the sample leading edge of the overhang in the direction of movement of the sample in regions accordingly the positions of the light emitter and the photodetectors takes place.
• the light barriers are interrupted by the sample leading edge of the overhang, so that electrical signals are obtained as a function of the length of the overhang. These signals are equivalent to the shape of the sample leading edge of the overhang.
• the distances between the light barriers can advantageously be switched on and locked.
• the optical measuring arrangement consists of a light barrier, wherein at least one light transmitter with a downstream in the beam path scanner optics spaced from the bending edge and a plurality of photodetectors are arranged on the bending edge, so that the position and consequently the shape of the sample leading edge of the overhang in Direction of movement of the sample is carried out according to the positions of the photodetectors.
• the scanner optics With the scanner optics, the light beam is guided parallel to the bending edge.
• a scanner optics is for example a pivoting mirror or a rotating polygon mirror.
• the overhang interrupts the optical connection between the scanner optics and the photodetector over the time of the repeating movement of the Scanner optics addition compound, so ⁇ ass the position of the sample leading edge of the
• the optical measuring arrangement consists of a light barrier, while at least one light transmitter via a coupled drive mechanism parallel to the bending edge of the device is movable and a plurality of photodetectors are arranged on the bending edge such that the position and, consequently, the shape of the sample leading edge of the overhang occurs in the direction of movement of the sample in accordance with the positions of the photodetectors.
• the light transmitter itself is moved.
• an image pickup device for receiving the regions of the incident on the sample light rays of the at least one light emitter is arranged. Furthermore, the image recording device is connected to an image evaluation device in such a way that the position of the regions of the sample with the incident light rays is determined.
• the optical measuring arrangement is according to the embodiment of claim 6, a spaced apart from the bending edge of the device image pickup device for receiving at least corresponding to the bending edge extending sample leading edge, the image pickup device is connected to an image evaluation so that the shape of this sample leading edge stored as a series digitally converted pixels and / or is displayed. In this case, the complete history of the shape of the sample leading edge of the overhang can be detected as a function of the overhang length.
• the fastening device are arranged on a guided slide or carriage, the drive coupled as a rotationally acting drive either with a drive spindle, wherein the drive spindle engages in a threaded nut of the carriage or carriage, or with a roller / a wheel of a traction drive coupled, wherein the carriage or carriage is connected to the traction means, and the position measuring device, a directly or indirectly measuring system.
• a simple guided method of the carriage or carriage is possible.
• the Positionsmesseinrich ⁇ ung is attached directly to the carriage or carriage.
• intermediate links transmit the position or distance change to a rotary measuring system.
• Intermediate links are the drive spindle or rack and pinion.
• the indirect measurement is structurally simpler and thus more economical than the direct measurement.
• the direct measuring system can advantageously consist of a pickup on the carriage or carriage and a scale on a fixed relative to the carriage or carriage part of the device.
• the indirectly measuring system is, for example, a pinion engaging a rack on a fixed part of the device and coupled to a rotary pickup either on the carriage or on the carriage or a rotary encoder coupled to the drive spindle or drive.
• the fastening device is arranged on a guided slide or carriage
• the drive is a linear drive with a linear motor
• the position measuring device is a direct or indirect measuring system.
• the linear motor can easily be integrated a position measuring device. About known distances of the steps can be easily determined the position of the carriage or the carriage.
• the fastening device is arranged according to the embodiment of claim 9 advantageously hinged to the carriage or carriage.
• the sample can be easily fixed in a fixed distance of the carriage or carriage relative to the bending edge.
• At least one linear guide of the fastening device is arranged according to the embodiment of claim 10 on a plate with a feed level for the sample, wherein the bending edge is arranged at right angles to the linear guide edge of the feed plane, and the feed plane and the optical measuring device an angle greater than 90 ° and smaller 180 °.
• the optical measuring arrangement thus represents an inclined plane to the feed level.
• the stiffnesses to the seam of adjacent surfaces can also be determined.
• the bending stiffness can be determined as a function of the seam distance.
• Textiles are in particular tissue, knitwear, scrim, or laminated and laminated combinations such as fabric with foam layer with or without a seam.
• Fig. 1 shows a device for determining the stiffness of flexible materials in a plan view
• Fig. 2 shows the device in a side view.
• a device for determining the stiffness of flexible materials consists essentially of a guided fastening device 6 for a sample of a flexible material with a position measuring device and a drive 11, a feed level 2 with a bending edge 3, an optical measuring arrangement for non-contact measurement of the position and therefrom inferring the shape of the front edge of the sample or the area of the overhang of the sample bending by its own weight after the bending edge 3 of the device and a control device connected to the position measuring device, the drive 11 and the optical measuring device.
• 1 shows a device for determining the stiffness of flexible materials in a basic plan view.
• the device for determining the stiffness of flexible materials has for this purpose a feed level 2 and an inclined plane 12 as a beam plane.
• the feed level 2 is preferably a surface of a plate 1, which is further provided with a frame 13, so that a table is realized.
• the plate 1 and thus the feed level 2 has two spaced-apart straight guides 4, 5 for the fastening device 6 of the sample, which is located in a traverse 8.
• the attachment means 6 for the sample is preferably a known releasable clamping device.
• a first linear guide 4 has a carriage 7 with the trolley 8 for the attachment means 6 of the sample, while the second linear guide 5 is formed as a slide rail for the traverse 8.
• the carriage 7 and the slide rail on the opposite side ensure a linear guide of the trolley 8 with the fastening device 6 parallel to the bending edge 3.
• the carriage 7 has a threaded nut into which a drive spindle 9 engages.
• the drive spindle 9 is rotatably mounted and coupled to a rotationally acting drive 11.
• the position measuring device for the carriage 7 at the feed level 2 is an indirectly measuring system.
• a rotary encoder 10 is coupled to the drive spindle 9.
• the rotary encoder 10 is a known digital-incremental measuring system with a grid disc. This gives a subdivision of the way.
• the bending edge 3 is arranged, wherein the bending edge 3 is a perpendicular to the linear guides 4, 5 arranged edge of the plate 1.
• the feed level 2 and the optical measuring arrangement which represents the inclined plane 12, are arranged at an angle to each other and close an angle greater than 90 ° and less than 180 ° one.
• the plate 1 with the feed level 2 and the optical measuring arrangement are hingedly connected to each other so that the angle between the feed level 2 and the optical measuring arrangement on and can be determined in this position.
• the optical measuring arrangement consists of a plurality of spaced-apart light barriers, the light emitter being arranged at a distance from the bending edge 3 and the photodetectors at the bending edge 3.
• the light emitters are known lasers, in particular so-called laser pointers, which are located in a holding device 14.
• the holding device 14 is connected via two spaced-apart webs 15 hingedly connected to the plate 1.
• the bending edge 3, the webs 15 and the holding device 14 define the inclined plane 12.
• the photo detectors of the photoelectric sensors are known phototransistors.
• the laser pointers are arranged, for example, in a grid of 12.5 mm. With a parallel placement of 17 laser pointers and an equal number of photodetectors, 3 measured values can be recorded with a sample width of 25 mm. With a sample width of 50 mm, the acquisition of 5 measured values and with a sample width of 200 mm, the acquisition of 17 measured values is given.
• the phototransistors are positioned just below the bending edge 3. These are structurally designed so that by means of a defined chamfer an exact angle adjustment for measured value recording is possible.
• the evaluation of the electronic signal of the receivers is done by means of a comparator circuit with hysteresis of the control device to prevent "flickering" in the border areas.
• the signals are read out directly as a binary word.
• the position measuring device, the drive 11 and the optical measuring arrangement are connected to the control device.
• the control device is preferably a component of a data processing system, for example in the form of a computer.
• the sample of the flexible material itself is a textile, a leather, a paper, a film or a coated or laminated material with or without a seam, so that in the presence of a seam, the seam stiffness and its influence on adjacent areas of the sample is taken into account ,
• the optical measuring arrangement consists of a light barrier, wherein a light emitter with a scanner optics arranged downstream of the beam path is arranged at the bending edge 3 and several photodetectors are arranged at the bending edge 3, so that the position and, consequently, the shape of the edge of the overhang in the direction of movement of the sample according to the positions of the photodetectors.
• the scanner optics is either a powered swivel mirror or a rotating polygon mirror.
• the optical measuring arrangement consists of a light barrier, wherein a light emitter is movable parallel to the bending edge 3 of the device via a drive mechanism coupled thereto and a plurality of photodetectors are arranged on the bending edge 3, so that the position and, consequently, the shape of the edge of the Overhang occurs in the direction of movement of the sample according to the positions of the photodetectors.
• the optical measuring arrangement is an image pickup device arranged at a distance from the bending edge 3 of the device for picking up at least the edge of the sample which corresponds to the bending edge 3.
• the image recording device is interconnected with an image evaluation device such that the shape of this sample leading edge is stored and / or displayed as digitally converted pixels arranged next to one another.
• the image pickup device is a known digital camera.
• the image evaluation device is advantageously part of the computer.
• an image pickup device for receiving the regions incident on the sample Light beams of the at least one light emitter arranged.
• the image recording device in the form of a digital camera is interconnected with an image evaluation device contained in the data processing system such that the position of the regions of the sample with the incident light rays is determined.

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• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
• Length Measuring Devices By Optical Means (AREA)

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• 2006
  • 2006-05-03 DE DE102006021726A patent/DE102006021726A1/de not_active Withdrawn
• 2007
  • 2007-05-03 WO PCT/DE2007/000840 patent/WO2007124742A2/fr active Application Filing
  • 2007-05-03 EP EP07722392A patent/EP2013605B1/fr not_active Not-in-force
  • 2007-05-03 AT AT07722392T patent/ATE509264T1/de active
  • 2007-05-03 DE DE112007000999T patent/DE112007000999A5/de not_active Withdrawn

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